Optical constants

Refractive index of KCl (Potassium chloride)

Querry 1987: n,k 0.22–167 µm

Data: tabulated nk
Range: 0.22–166.7 µm
Points: 311
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.48562
Extinction coefficient k: 0

Permittivity ε₁: 2.20707
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: -0.05 µm⁻¹

Group index n_g: 1.515
Group velocity dispersion: — fs²/mm

Dispersion parameter D: — ps/(nm·km)
Photon energy: 2.11001 eV

ε = (n + ik)², α = 4πk/λ, n_g = n − λ dn/dλ, GVD = λ³/(2πc²) d²n/dλ², D = −(λ/c) d²n/dλ². Group-velocity dispersion is given for formula data only.

Use it in Lightsmith

Load this data in Python, simulate in one more line

pip install lightsmith

import lightsmith as ls

# KCl (Potassium chloride): Querry 1987: n,k 0.22–167 µm
kcl = ls.fetch_refractiveindex("main", "KCl", "Querry", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(kcl.range_nm)  # (220, 166667) nm
eps = kcl.eps([633])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_2207ead7c2e0/lightsmith"
kcl = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(kcl.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (kcl/querry-1987).

# ... load kcl as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=kcl)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength

Same spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).

Materials guide Open a sphere of it in Studio Quick start Ask the community

Lightsmith is open source (MIT): Mie, T-matrix, BEM, DDA, FDTD, RCWA, TMM, mode solvers and inverse design behind one spec, on CPU or GPU. GitHub.

References

M. R. Querry. Optical constants of minerals and other materials from the millimeter to the ultraviolet, Contractor Report CRDEC-CR-88009 (1987)

Cite

M. R. Querry. Optical constants of minerals and other materials from the millimeter to the ultraviolet, Contractor Report CRDEC-CR-88009 (1987); Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

312 rows as published

CSV comma separated TXT tab separated YAML n, k Full database record original YAML All quantities CSV JSON metadata

KCl (Potassium chloride), Querry 1987: n,k 0.22–167 µm: n and k versus wavelength
λ (µm)	n	k
0.22	1.636	0.0
0.24	1.593	0.0
0.26	1.567	0.0
0.28	1.55	0.0
0.3	1.538	0.0
0.32	1.53	0.0
0.34	1.523	0.0
0.36	1.515	0.0
0.38	1.51	0.0
0.4	1.506	0.0
0.42	1.503	0.0
0.44	1.499	0.0
0.46	1.495	0.0
0.48	1.492	0.0
0.5	1.49	0.0
0.52	1.488	0.0
0.54	1.487	0.0
0.56	1.486	0.0
0.58	1.486	0.0
0.6	1.485	0.0
0.62	1.485	0.0
0.64	1.484	0.0
0.66	1.484	0.0
0.68	1.484	0.0
0.7	1.484	0.0
0.72	1.484	0.0
0.74	1.484	0.0
0.76	1.484	0.0
0.78	1.484	0.0
0.8	1.485	0.0
0.82	1.485	0.0
0.84	1.486	0.0
0.86	1.486	0.0
0.88	1.486	0.0
0.9	1.486	0.0
0.92	1.487	0.0
0.94	1.487	0.0
0.96	1.487	0.0
0.98	1.488	0.0
1.0	1.488	0.0
1.02	1.488	0.0
1.04	1.489	0.0
1.06	1.489	0.0
1.08	1.489	0.0
1.1	1.489	0.0
1.12	1.49	0.0
1.14	1.49	0.0
1.16	1.49	0.0
1.16	1.49	0.0
1.2	1.489	0.0
1.22	1.489	0.0
1.24	1.489	0.0
1.26	1.489	0.0
1.28	1.488	0.0
1.3	1.488	0.0
1.32	1.488	0.0
1.34	1.488	0.0
1.36	1.488	0.0
1.38	1.488	0.0
1.4	1.487	0.0
1.42	1.487	0.0
1.44	1.487	0.0
1.46	1.487	0.0
1.48	1.487	0.0
1.5	1.486	0.0
1.52	1.486	0.0
1.54	1.486	0.0
1.56	1.486	0.0
1.58	1.486	0.0
1.6	1.486	0.0
1.62	1.486	0.0
1.64	1.486	0.0
1.66	1.486	0.0
1.68	1.486	0.0
1.7	1.485	0.0
1.72	1.485	0.0
1.74	1.485	0.0
1.76	1.485	0.0
1.78	1.485	0.0
1.8	1.485	0.0
1.82	1.485	0.0
1.84	1.485	0.0
1.86	1.485	0.0
1.88	1.485	0.0
1.9	1.485	0.0
1.92	1.485	0.0
1.94	1.485	0.0
1.96	1.485	0.0
1.98	1.485	0.0
2.0	1.484	0.0
2.02	1.484	0.0
2.04	1.484	0.0
2.06	1.484	0.0
2.08	1.484	0.0
2.1	1.484	0.0
2.12	1.483	0.0
2.14	1.483	0.0
2.16	1.483	0.0
2.18	1.483	0.0
2.2	1.482	0.0
2.22	1.482	0.0
2.24	1.482	0.0
2.26	1.482	0.0
2.28	1.482	0.0
2.3	1.482	0.0
2.32	1.481	0.0
2.34	1.481	0.0
2.36	1.48	0.0
2.38	1.48	0.0
2.4	1.48	0.0
2.42	1.479	0.0
2.44	1.479	0.0
2.46	1.479	0.0
2.48	1.478	0.0
2.5	1.478	0.0
2.5126	1.478	0.0
2.5253	1.478	0.0
2.5381	1.478	0.0
2.551	1.478	0.0
2.5641	1.478	0.0
2.5773	1.478	0.0
2.5907	1.478	0.0
2.6042	1.478	0.0
2.6178	1.478	0.0
2.6316	1.478	0.0
2.6455	1.478	0.0
2.6596	1.478	0.0
2.6738	1.478	0.0
2.6882	1.478	0.0
2.7027	1.478	0.0
2.7174	1.478	0.0
2.7322	1.478	0.0
2.7473	1.478	0.0
2.7624	1.478	0.0
2.7778	1.478	0.0
2.7933	1.478	0.0
2.809	1.478	0.0
2.8249	1.478	0.0
2.8409	1.478	0.0
2.8571	1.478	0.0
2.8736	1.478	0.0
2.8902	1.478	0.0
2.907	1.478	0.0
2.924	1.477	0.0
2.9412	1.477	0.0
2.9586	1.477	0.0
2.9762	1.477	0.0
2.994	1.477	0.0
3.012	1.477	0.0
3.0303	1.477	0.0
3.0488	1.477	0.0
3.0675	1.477	0.0
3.0864	1.477	0.0
3.1056	1.477	0.0
3.125	1.477	0.0
3.1447	1.477	0.0
3.1646	1.477	0.0
3.1847	1.477	0.0
3.2051	1.477	0.0
3.2258	1.477	0.0
3.2468	1.477	0.0
3.268	1.476	0.0
3.2895	1.476	0.0
3.3113	1.476	0.0
3.3333	1.476	0.0
3.3557	1.476	0.0
3.3784	1.476	0.0
3.4014	1.476	0.0
3.4247	1.476	0.0
3.4483	1.476	0.0
3.4722	1.476	0.0
3.4965	1.476	0.0
3.5211	1.476	0.0
3.5461	1.476	0.0
3.5714	1.476	0.0
3.5971	1.476	0.0
3.6232	1.476	0.0
3.6496	1.476	0.0
3.6765	1.475	0.0
3.7037	1.475	0.0
3.7313	1.475	0.0
3.7594	1.475	0.0
3.7879	1.475	0.0
3.8168	1.475	0.0
3.8462	1.475	0.0
3.876	1.475	0.0
3.9063	1.475	0.0
3.937	1.475	0.0
3.9683	1.475	0.0
4.0	1.475	0.0
4.0323	1.475	0.0
4.065	1.475	0.0
4.0984	1.475	0.0
4.1322	1.475	0.0
4.1667	1.474	0.0
4.2017	1.474	0.0
4.2373	1.474	0.0
4.2735	1.474	0.0
4.3103	1.474	0.0
4.3478	1.474	0.0
4.386	1.474	0.0
4.4248	1.474	0.0
4.4643	1.474	0.0
4.5045	1.474	0.001
4.5455	1.474	0.0
4.5872	1.473	0.0
4.6296	1.473	0.001
4.6729	1.473	0.0
4.717	1.473	0.001
4.7619	1.473	0.0
4.8077	1.472	0.001
4.8544	1.472	0.001
4.902	1.472	0.001
4.9505	1.472	0.001
5.0	1.472	0.001
5.0505	1.472	0.001
5.102	1.472	0.001
5.1546	1.471	0.001
5.2083	1.471	0.001
5.2632	1.471	0.002
5.3191	1.471	0.001
5.3763	1.47	0.002
5.4348	1.47	0.002
5.4945	1.47	0.002
5.5556	1.47	0.002
5.618	1.47	0.002
5.6818	1.47	0.003
5.7471	1.47	0.002
5.814	1.469	0.003
5.8824	1.469	0.003
5.9524	1.469	0.003
6.0241	1.469	0.003
6.0976	1.469	0.003
6.1728	1.468	0.003
6.25	1.468	0.003
6.3291	1.468	0.004
6.4103	1.468	0.004
6.4935	1.468	0.004
6.5789	1.468	0.004
6.6667	1.468	0.004
6.7568	1.467	0.004
6.8493	1.467	0.004
6.9444	1.467	0.005
7.0423	1.467	0.004
7.1429	1.466	0.005
7.2464	1.466	0.005
7.3529	1.466	0.005
7.4627	1.466	0.005
7.5758	1.466	0.005
7.6923	1.465	0.005
7.8125	1.465	0.005
7.9365	1.465	0.005
8.0645	1.464	0.005
8.1967	1.464	0.005
8.3333	1.464	0.005
8.4746	1.463	0.005
8.6207	1.463	0.005
8.7719	1.462	0.005
8.9286	1.462	0.005
9.0909	1.461	0.005
9.2593	1.46	0.005
9.434	1.46	0.005
9.6154	1.459	0.005
9.8039	1.458	0.005
10.0	1.458	0.005
10.2041	1.457	0.005
10.4167	1.456	0.004
10.6383	1.455	0.005
10.8696	1.454	0.005
11.1111	1.453	0.004
11.3636	1.451	0.004
11.6279	1.45	0.005
11.9048	1.448	0.005
12.1951	1.447	0.006
12.5	1.445	0.006
12.8205	1.444	0.006
13.1579	1.442	0.007
13.5135	1.44	0.007
13.8889	1.439	0.008
14.2857	1.437	0.008
14.7059	1.435	0.008
15.1515	1.433	0.008
15.625	1.43	0.008
16.129	1.427	0.008
16.6667	1.424	0.008
17.2414	1.42	0.006
17.8571	1.415	0.006
18.5185	1.411	0.006
19.2308	1.404	0.004
20.0	1.396	0.003
20.8333	1.386	0.005
21.7391	1.378	0.006
22.7273	1.367	0.005
23.8095	1.354	0.006
25.0	1.338	0.005
26.3158	1.318	0.007
27.7778	1.297	0.01
29.4118	1.269	0.009
31.25	1.229	0.008
33.3333	1.174	0.013
35.7143	1.093	0.023
38.4615	0.979	0.067
41.6667	0.843	0.162
45.4545	0.553	0.411
50.0	0.566	0.569
55.5556	0.311	1.149
62.5	0.303	2.425
71.4286	5.5	3.337
83.3333	3.01	0.249
100.0	2.561	0.186
125.0	2.36	0.173
166.6667	2.29	0.154

Optical transmission calculator

Free-standing sample in vacuum, normal incidence

Transmittance T: —
Reflectance R: —

Fresnel reflection calculator

R_p: —
R_s: —
R = (R_p+R_s)/2: —
Phase φ_p: —
Phase φ_s: —
Brewster angle θ_B: —
Critical angle θ_C: —

KCl (Potassium chloride): all datasets

About KCl (Potassium chloride)

Potassium chloride (KCl) is a salt that finds use in various optical applications due to its wide spectral transmission range. Like its bromide counterpart, potassium chloride is hygroscopic, requiring cautious handling and storage conditions to preserve its optical qualities. It is commonly used as a prismatic or plane-parallel component in infrared spectroscopy, particularly because of its low cost and good transmission in the mid and far-infrared regions. Additionally, it serves as a substrate for specialized optical coatings. Due to its moisture sensitivity, it's less suitable for applications exposed to high humidity or varying environmental conditions. Nonetheless, KCl remains an important material in the toolkit of optical engineers and scientists.

Potassium chloride - Wikipedia

More about KCl (Potassium chloride) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/KCl/nk/Querry.yml
ID: ds_2207ead7c2e0
API: /v1/datasets/ds_2207ead7c2e0

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